Fireproof stairway.



No. 802,506. PATENTED OCT. 24, 1905. F. 0. HANSON.

FIREPROOF STAIRWAY.

APPLIoATIoN FILED MAY 10.1905.y

FRANCIS O. HANSON, OF CHICAGO, ILLINOIS.

FHREPHOOF STAIIWAY..

YNo. 802,506.

Speccaton of Letters Patent.

Patented Oct. 24, 1905.

Application iled May 10, 1905. Serial No. 259.840.

To rtl/Z who/it it 7er/ty concern.'

Be it known that I, FRANCIS O. HANsoN, a citizen of the United States, residing at Chicago, in the county oic Cook and State oi' Illinois, have invented certain new and useful Improvements in Fir-eproot' Stairways, of which the following is a full, clear, and exact spcci- Iication.

My invention relates more particularly to the class of lireproof stairways composed or' metallic members bolted or otherwise secured together in combination with a concrete or other iireprootl lling to constitute the body of the step; and it has for its primary object to provide an improved form of iireproof stairway which will be light and consequently economical in construction, and at the same time will possess the maximum degree ot' strength, the further object being to make a stairway of the desired character of knockeddown form, so that the various parts may be shipped to the place of use in a compact form, also avoiding the liability of breakage, and readily set up without requiring any special degree oi' skill.

l/Vith a view to the attainment of these ends and the accomplishment of certain other objects that will hereinafter appear the invention consists in the features of novelty in the construction, combination, and arrangement of parts, which will now be described with reference to the accompanying drawings and more particularly pointed out in the claims.

In the said drawings, Figure I is a vertical longitudinal sectional View of a stairway constructed according to my invention, and Fig. 2 is a vertical cross-section thereof with the concrete omitted.

In carrying out my invention I employ the usual side stringers A, which may be coinposed oi' cast-iron or any other suitable material and upon which at proper intervals apart are cast, formed, or otherwise attached supporting lugs B, having their faces arranged in horizontal planes. Upon these lugs B are supported angle-irons C or other suitable connecting members, which tie the stringers A together, the angle-irons being secured in an inverted position upon the lugs B by means of stove-bolts or any other suitable device. Extending across the stairway irons C by bolts, rivets, or other suitable devices (Z and the bolts Z), the lower edge of each being attached to the upright flange of the angle-iron, while the upper edge rests upon and is attached to the horizontal angle of the next angle-iron by the bolt I), the edges ot' the arch D resting against the inner faces of both oi' the angle-irons. The stringers A are also formed with the lugs E, which have vertical faces for the attachment ot' the risers F, the attachment being effected by stove-bolts @or other suitable means, with the nuts arranged inside. The upper edge oil the riser is formed with anosing I-l, extending even with the level ofthe stair-tread, while the lower end is formed with a return-bend or Hangs I, located a considerable distance above the upper edge of the arch D. The metallic portion of the stair being thus put together, the space between the arch D and the riser F is then iilled with concrete G or any other suitable material, which molds itself to the contour of the arch D and which may be leveled off between the Lipper edge of the nosing I-I and the upper surface of the return I to produce a level tread. The concrete G linds its way down into the narrow space between the riser F and the lower end oi the arch D, where the concrete constitut'- ing the upper edge oi' the next step below also enters under thc return I, and thus constitutes practically a continuation of the concrete filling. With the stair thus constructed it will be seen that the concrete filling assumes an arched formation like the sheet-metal arch D, and consequently after it sets possesses the strength of a perfect arch and aids the arch D in sustaining' the weight directly upon the cross connections or angle-irons C, upon which both ends of the concrete lilling rest. Consequently I am enabled to save the concrete material that is displaced by an upward arching' or' the plate D, and thus not only cheapen thc construction in that item, but reduce the weig'ht to which the stringers and other metallic members are subjected, and consequently lessen the cost of these parts without detracting from the strength of the structure.

Having thus described my invention, what I claim as new therein, and desire to secure by Letters Patent, isM

l. In a lireproot' stairway the combination of the string'ers, bars connecting the stringers together, an arched plate extending between the stringers, and a concrete body supported IOO IIO

at its upper and lower ends upon,said bars and arched upwardlg7 on its under side to Conform to said plate.

2. In a iireprootI stairway the combination of the stringers, bars connecting the stringers together, risers connecting the stringers and having their lower edges arranged above said bars, plates connecting said bars together and forming cavities with said risers, and Concrete fillings in said cavities, the upper portion of one filling being' extended below the lower end of the next iilling above and under the lo'wer edge of the riser.

3. In a ireproof stairway the combination of the stringers, risers connecting the stringers together and having return-bends at their lower edges, the return-bend of one riser beving substantially level with the upper edge `of the next riser below, and concrete fillings constituting the body portion of the steps, extending between said risers and under said return-bends. i

4L. In a fireproof stairway the Combination of the stringers, having lugs, angle-irons detachably secured to said lugs and connecting' the stringers together, an arched plate having its lower edge connected to the upright flange of one of said angle-irons and its upper edge connected to the horizontal flange of the next angle-iron above, a riser having its ends detaehably secured to the stringers, in front of said arched plate and forming a Cavity, and a concrete filling located in said cavity upon said arched plate.

FRANCIS O. HANSON. vWitnesses:

FRANCIS A. HOPKINS, A. M. UHER. 

